Pivot centre for articulated locomotives



Oct. 11, 1955 J. HADFIELD 2,720,432

PIVOT" CENTER FOR ARTICULATED LOCOMOTIVES Filed Oct. 2, 1950 4Sheets-Sheet 1 Oct. 11, 1955 J. HADFIELD 2,720,432

PIVOT CENTER FOR ARTICULATED LOCOMOTIVES Filed Oct. 2, 1950 4Sheets-Sheet 3 Oct. 11, 1955 HADFIELD 2,720,432

PIVOT CENTER FOR ARTICULATED LOCOMOTIVES Filed Oct. 2, 1950 4Sheets-Sheet 4 f'fms, ll

lnven for W W ByJZ-MW S 215%.

A rneys United Sttes Patent dice 2,720,432 Patented Oct. 11, 1955 PIVOTCENTRE FOR ARTICULATED LOCOMOTIVES James Hadfield, Romiley, Chester,England Application October 2, 1950, Serial No. 187,891

14 Claims. (Cl. 308-437) This invention, an application which is acontinuationin-part .of my copending U. S. application Ser. No. 783,991filed November 4, 1947, now abandoned, relates to articulatedlocomotives and like vehicles, that is to say vehicles in whicharticulated or pivoted joints are used, and is concerned with thepivotal centre pieces or .pivot centres of such vehicles.

1 In articulated locomotives and like vehicles experience has shown thattwo major difiiculties arise in practice with the pivot centres;firstly, difliculties are experienced in taking up the slack caused byWear of the pivotal centre pieces; and secondly, in providing thenecessary means to permit tilting or angular movements in verticalplanes to take place between the male and female members of the pivotcentres.

In seeking to obviate the first of these difficulties it has previouslybeen proposed to provide for the pivot centres renewable wearing blocksof the kind adjusted by wedges acting at right angles to the axes of thepivots. In practice it is found that in articulated locomotives and likevehicles such devices as are at present employed are diflicult tooperate, in as much as they are usually of necessity located inpositions which are diflicult of access, and moreover they require theassistance of external forces of considerable magnitude usually in theform of additional locomotive power with which to slide the male andfemale parts of the pivot centres relative to each other into theappropriate positions such as will enable the wedges to be adjusted inorder to take up the slack.

In seeking to obviate the second difficulty it has previously beenproposed to make provision for the tilting or angular movements invertical planes between the male and female parts of the pivot centresby providing clearances between the mating parts when such parts arecylindrical in form or alternatively to make such partshemispherical inform. In the case of the cylindrical form of pivot the provision of therequisite clearance to permit the necessary tilting or vertical angularmovements between the male and female parts of the pivot centres leadsto considerable vibration and hammering action when the articulatedlocomotive or like vehicle is at Work, and consequential wear and damageis caused both to the pivot centres themselves and to other detail partsof the locomotives or like vehicles.

Moreover, in order tominimise the amount of clearance required to permitthe tilting or vertical angular movements to take place it haspreviously been found necessary to severely limit the depth of thevertical mating faces of the male and female parts of the pivot centre.

In the case of the hemispherical form of pivot centre it frequentlyhappens that there is not sufiicient space to accommodate the increaseddepth necessitated by this form of construction, and moreover the partsare ex pensive to manufacture and repair.

One object of the present invention is the provision of means forobviating the difiiculty in taking up the slack caused by wear of thepivotal centre pieces.

Another object is to provide improved and simple means to permit tiltingor angular movements in vertical planes to take place between the maleand female members, which means will be free from the objection as tovibrating and hammering, and will not involve undue expense or theoccupation of undue space.

In order that the invention may be more readily understood, reference ishereby made to the accompanying drawings wherein:

Figure 1 is a vertical section showing one example of an articulationsystem constructed according to the invention;

Figure 2 is a vertical section on the line A-A of Figure 1;

Figure 3 is a sectional plan on the line B-B of Figure 1;

Figure 4 is a plan view of Figure 2;

Figures 5 and 6 are diagrams in elevation and plan of a modification;and

Figures 7 and 8 are sectional and elevational diagrams of a furthermodification;

Figure 9 is a view of an optional detail; and

Figure 10 is an enlarged view of the pivot centre.

Figure 11 is a similar view to Figure 10 illustrating a slightmodification.

Referring to the drawings the type of vehicle to which the articulationsystem is applied is an articulated locomotive of the well known type inwhich three units are articulated together end to end, the centre unitbeing a boiler unit which comprises the boiler and the cab, and each endunit being an engine unit which includes cylinders and driving wheels.of the framework of the boiler unit, designated by the reference F1overhanging part of the framework of oneof the engine units, designatedby the reference F2, and the pivot centre which is the subject of thepresent invention serves to connect the said framework part F1 to theframework part F2 so as to permit of pivoting about a vertical axis, thepivotal connection also being such that the framework part F2 supports adownward thrust of the framework part F1, or, in other words, such thatthe engine unit supports a due proportion of the weight of the boilerunit. It will be understood that the pivot centres connecting the boilerunit to both engine units.

are similar, and that the pivot centres transmit the tractive and bulferforces between the engine unit and the boiler unit.

The numeral 1 designates the metallic male member of the pivot centre,supported on the framework part F2, and 23 designates the metallicfemale member which embraces said male member and is constructed in twoparts, one of which constitutes an adjustable wearing block 3, a gap 2abeing left to permit the necessary movement to effect the requiredadjustment for wear. Said female member is carried by the framework partF1.

The adjustable block 3 is mounted in a casing memher 4 of said frameworkpart F1 and its edge face 311 is inclined as shown. In a side extension4a of the casing member 4 an adjustable wedge 5 is housed, this wedge 5having an inclined face 5a corresponding to and in co-operativeengagement with the inclined face 312 of the adjustable block 3. Wedgeactuating rods 6 pass upwardly and loosely through holes in the wedge 5and nuts or heads 6a are provided upon which the wedge 5 is supported, aflanged saddle-bracket 7 engaging the undersides of the heads 6a. Theserods 6 pass through guided bearings 4b in bosses 4c in the diaphragm orplatform 4d of the structural framework F1 and their upper extremitiesextend into guides 7a in plugs 7b The drawings show part.

2 mounted in the top wall of the framework. At positions intermediatetheir ends the rods 6 are screw threaded as indicated at 612 andnut-like devices 8 located between the bottoms of the plugs 7b and thebosses 4c upstanding from the diaphragm or platform 4d of the frameworkP1.

In the arrangement shown in Figures 1 to 4 the peripheries of thesenut-like devices are shaped in the form of worm wheels and are meshedwith actuating screws 9 keyed on to spindle 9a supported in bearings 10in the structural framework F1 and in a bearing 11 in the wall of wing42 extending from the framework. The outer extremity of the spindle 9ais provided with an operating wheel or handle 12 conveniently locatedfor operation. -In operation rotation of this actuating screw 9 effectsrotation of the nut-like devices 8, which coacting with the screwthreads 6b cause axial movement of the wedge actuating rods 6 so thatthe wedge S can be caused to cooperate with the adjustable bearing block3 and thus any desired adjustment to compensate for wear between themale and female members of the pivot centre can be effected at will.

It is to be understood that other forms of gearing for effectingsynchronous actuation of the wedge actuating rods 6 can be adopted. Forexample in Figures 5 and 6 there is indicated a method where gear wheels13 meshing with the toothed nut-like devices 8 are employed and operatedby a hand wheel 14 and in Figures 7 and 8 an arrangement is indicatedwhere the actuating screws 9 are replaced by bevel pinions 15 keyed onto spindle 9a, and meshing with bevel wheels 16 on the wedge actuatingrods 6. It will be understood that in both these cases the rods 6 musthave facility for axial movement and a power ratio factor which willrender the manual operation effective to overcome the resistance to bemet.

. It will be seen that, by the above mechanisms the adjustments caneasily be made and maintained from positions which are freelyaccessible, and that a high mechanical advantage is provided sufficientto magnify a reasonable manual effort on the part of the operator into aforce of sufficient magnitude to overcome the frictional resistance tosliding movement between the horizontal faces of the male and femaleparts of the pivot centre which arise from the vertical loadspermanently carried on these faces irrespective of whether or not thearticulated locomotive is at work.

The means to obtain this high mechanical advantage is such as to enablethe required adjustments to be made with a minimum amount of effort onthe part of the operator and without the assistance of the largeexternal forces previously required when adjusting the pivot centres ofarticulated locomotives and said means ensures the maintenance of thewearing blocks securely in their adjusted position.

A supplement or alternative to these manually operable mechanisms isillustrated in Figure 9.

In this case compression springs 17 are interposed between the heads ofthe plugs 7b and the bosses 4c. If the springs are sufficiently strongto draw up the wedge automatically as wear Occurs no further provisionfor compensating for wear would be necessary but by providing the plugs71) with screw threads engaging screw threads on the rods 6 positiveadjustments can be effected from time to time if desired, by manuallyscrewing said plugs '7 b so that they engage the bosses 40. Thus meansare provided by which the wear is taken up automatically, and if for anyreason the springs should fail the Wear can be taken up positively bymanual operation.

As has been before indicated it is necessary to provide for tiltingmovements between the male and female members of the pivot centre. Themethod employed according to the present invention is shown particularlyin Figure 10. The male member 1 is given the form of a truncated coneand the female member, consisting of the two parts 2 and 3 beforedescribed, is similarly coned. The dotted lines illustrate the actionwhen the tilt is in one direction but it will be understood that similarconditions obtain in whatever direction relative to the axis tiltingtakes place. It will be seen that normally the tapered surfaces of saidtwo members mate to provide for slipping pivotal movement of saidmembers relative to each other about a vertical axis, and that tiltingmovement of said members relative to each other in vertical planes ispermitted accompanied by partial withdrawal of said members relative toeach other. When withdrawal occurs, the faces of said male and femalebearing members which are normally in full contact with each otherseparate, and upon tilting of one of the bearing members relative to theother contact between the bearing faces is reestablished only atopposite ends of the male bearing member and on opposite sidesrespectively of the axis of the bearing members.

Instead of the cone of the male and female members having a straightline generatrix as in Figure 10 it may have a convexly curved generatrixas in Figure 11.

The diameter of the male member at the face which first enters thefemale member will, of course, in all cases be smaller than the diameterat its other face.

The foregoing construction has the advantages that freedom of movementbetween the male and female parts of the pivot centres is securedWithout clearances and with consequent reduction in wear; an increase inthe depth of bearing surface is practicable when compared with the usualcylindrical construction which also tends to reduce wear. Thepossibility of oil leaking away through clearance spaces withoutadequately lubricating the bearingsurfaces is completely eliminated.

A further advantage of the form of construction now proposed is that itpermits the use of mating surfaces having greater depth of contact thanwas previously practicable with the cylindrical form of pivot.

It may be pointed out that the advantages of operating the wedge in avertical direction, instead of, as heretofore, in a horizontal directionare, first, that it enables the manual adjusting element to beconveniently arranged at an accessible position. In addition it permitsthe provision of maximum bearing surfaces at all stages of adjustment towithstand the applied loading and said bearing surfaces aresymmetrically disposed relative to the axis of the pivot members andsupport the adjusting blocks over the whole width thereof at all stagesof adjustment.

It is to be understood that all the arrangements hereinbefore describedare equally applicable to pivot centres of articulated locomotives andlike vehicles irrespective of whether the male member is located abovethe female member or vice versa.

What I claim is:

1. Pivot centre for articulated locomotives comprising a rigid circularbearing support, a circular male bearing member having a circularbearing face mounted on said support, a fixed female bearing elementhaving a substantially semi-circular inner face contacting with the faceof the male bearing member, a laterally movable female bearing elementhaving a substantially semi-circular inner face contacting with the malebearing member in opposed relation to and separated by a gap from thefixed female bearing element, the two elements constituting thefemale-bearing, the outer face on the movable bearing element beinginclined to the vertical longitudinal axis of said male bearing member,a vertically adjustable wedge in co-operative contact with said inclinedface, vertically disposed headed wedge adjusting rods passing looselythrough holes in said wedge, the heads of said rods being in contactwith the wedge, guides at the ends of the rods remote from the heads andmeans for causing the rods to move vertically with the wedge to effectlateral adjustment of the movable female element of the female bearing.

2. Pivot centre for articulated locomotives comprising a rigid circularbearing support, a circular male bearing member mounted on said support,a fixed female bearamass ing element having a substantiallysemi-circular inner face contacting with the male bearing member,'alater ally movable female bearing element having a'substantiallysemi-circular inner face contacting with the male bearing member inopposed relation to and separated by a gap from the fixed female bearingelement,tl1e two elements constituting the female bearing, the outerface on the movable bearing element being inclined to the verticallongitudinal axis of said male bearing member, a vertically adjustablewedge in co-operative contact with said inclined face, verticallydisposed headed wedge adjusting rods passing loosely through holes insaid wedge, the heads of said rods being in contact with the wedge,guides at the ends of the rods remote from said heads, screw threads onsaid rods intermediate their ends, nut devices engaging said screwthreads and means for simultaneously actuating said nut devices toeffect vertical movement of said adjusting wedge to effect lateraladjustmerit of the movable female bearing element.

3. Pivot centre for articulated locomotives according to claim 2 whereinthe nut devices are provided with peripheral teeth and are allsimultaneously actuated by a common actuating device.

4. Pivot centre for articulated locomotives according to claim 2 whereinthe nut devices are provided with peripheral teeth and are allsimultaneously actuated by a screw threaded rod.

5. Pivot centre for articulated locomotives according to claim 1 whereinthe male bearing member is in the form of a truncated cone and thefemale bearing is of corresponding contour.

6. Pivot centre according to claim 1 wherein the contacting faces ofsaid male bearing member and female bearing are curved, the diameter ofthe male member at the face which first enters the female bearing beingsmaller than the diameter at its other face.

7. Pivot centre for articulated locomotives according to claim 1 whereinthe wedge adjusting rods are actuated by springs.

8. Pivot centre for articulated locomotives, comprising a verticallydisposed circular male bearing member, a. female bearing element havingan arcuate inner face contacting with said male bearing member, alaterally adjustable female bearing element having an arcuate inner facecontacting with said male bearing member in opposed relation to saidfirst-named female bearing element and an outer face inclined to thevertical longitudinal axis of said male bearing member, the two femalebearing elements constituting the female bearing, a verticallyadjustable wedge in co-operative relation with said outer face on theadjustable female bearing element, vertically disposed headedwedge-adjusting pull rods passing through holes in said wedge with theirheads engaging said wedge, and means for applying tension to said pullrods and thereby causing them to move vertically and thereby to pullsaid wedge vertically to effect lateral adjustment of the adjustablefemale bearing element.

9. Pivot centre for articulated locomotives, comprising a verticallydisposed circular male bearing member, a female bearing element havingan arcuate inner face contacting with said male bearing member, alaterally adjustable female bearing element having an arcuate inner facecontacting with said male bearing member in opposed relation to saidfirst-named female bearing element and an outer face inclined to thevertical longitudinal axis of said male bearing member, the two femalebearing elements constituting the female bearing, a verticallyadjustable wedge in co-operative relation with said outer face of saidadjustable female bearing element, vertically disposed wedge-adjustingpull rods connected to said Wedge, and helical springs coiled on saidrods and effecting a biasing pull on said rods and said wedge in thedirection to adjust said adjustable female bearing element laterallyagainst said male bearing member for taking up wear.

10.Pivot centre for articulated locomotives, comprising a verticallydisposed circular male bearing member, a female bearing element havingan arcuate inner face contacting with said male bearing member, alaterally adjustable female bearing element having an arcuate inner facecontacting with said male bearing member in opposed relation to saidfirst-named female bearing elem erit and an outer face inclined to thevertical longitudinal axis of said male bearing member, the two femalebearing elements constituting the female bearing, a verticallyadjustable wedge in cooperative relation with said outer face of saidadjustable female bearing element, vertically disposed wedge-adjustingpull rods connected to said wedge, a structure supporting saidadjustable female element against movement axially of the pivotrelatively to said male member, nuts screwed on said pull rods, andhelical springs coiled on said pull rods and in compression between saidnuts and said structure and thereby effecting a biasing pull on saidrods and said wedge in the direction to adjust said adjustable femalebearing element laterally against said male bearing member for taking upwear.

11. Pivot centre for articulated locomotives, comprising a verticallydisposed circular male bearing member, a female bearing element havingan arcuate inner face contacting with said male bearing member, alaterally adjustable female bearing element having an arcuate inner facecontacting with said male bearing member in opposed relation to saidfirst-named female bearing element and an outer face inclined to thevertical longitudinal axis of said male bearing member, the two femalebearing elements constituting the female bearing, a verticallyadjustable wedge in co-operative relation with said outer face of saidadjustable female bearing element, vertically disposed wedge-adjustingpull rods connected to said wedge, a structure supporting saidadjustable female element against movement axially of the pivotrelatively to said male member, nuts screwed on said pull rods, andhelical springs coiled on said pull rods and in compression between saidnuts and said structure and thereby effecting a biasing pull on saidrods and said wedge in the direction to adjust said adjustable femalebearing element laterally against said male bearing member for taking upwear, said nuts, when screwed on said rods in the direction to compresssaid springs, making contact with said structure and thereby positivelyadjusting said wedge in the direction to adjust said adjustable femalebearing element laterally against said male bearing member.

12. Pivot centre for articulated locomotives comprising a verticallydisposed circular, tapered male bearing member, a female bearing elementhaving a complementary tapered arcuate inner face contacting with saidmale bearing member, a laterally adjustable female bearing elementhaving a complementary tapered arcuate inner face contacting with saidmale bearing member in opposed relation to said first-named femalebearing element and an inclined outer face, the two female bearingelements constituting the female bearing member, wedge means cooperativewith said inclined outer face of said adjustable female bearing element,and spring means urging said wedge means in a direction to move saidadjustable female bearing element laterally against said male bearingmember for taking up Wear, said male and female bearing members beingpartially withdrawable from and tiltable relative to each other invertical planes accompanied by separation of the normally fullycontacting faces of said bearing members and reestablishing contactbetween the faces of said relatively tilted male and female bearingmembers only at opposite ends of said male bearing member and onopposite sides respectively of the axis of said bearing members.

13. A pivot centre as defined in claim 12 wherein said complementarytapered surfaces of said male and female bearing members have a straightline generatrix.

, 14. A pivot centre as defined in clairfflZ wherein said complementarytapered surfaces of said male and female bea ing members have a curvedgeneratrix.

References Cited in the file of this patent UNITED STATES PATENTS274,058 Tibbles Mar. 13, 1883 392,732 Hutchinson Nov, 13, 1888 446,296Schoen Feb. 10. 1 91 10 2,258,640

8 Davidson Oct. 10, 18 93 Ra hbun --1 V 0C1. 8, 9,18 Pitkin w'J uly 231925. Volk 2 Feb, 27, 1934 Marti Oct. 1, 1935 Kjolseth Feb.'9, 19,37Walton Sept. 7, 1937 Campion Jan. 17, 1939 Jackson Jan. 28, 1941Beckette Oct. 14, 1941

